Pneumatic drill.



' No. 694,7I4. K 4Patents-sd Mar. 4, |902;

` Tf. BARI'UW.l Y

PNEUMATlC-DRILL. (Application med im. 29, moo.) y (nu nodal.) 3 sheets-sheet l.

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Patented Mar. 4, |902.`

` lo. 694,7I-4.

T.' BAnRow.

PNEUMATIC DRILL.

` (Applica'tion mea out. 29, 1900.)

3 Sheets--Sheet 2.

(No Model.)

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No. 694,7l4.'

Patented Mar. 4, |902. T. BARRUW. PNEUMATIG DRILL.

(Application med oct'. 29. `190m 3 Sheets-Sheet 3.

' (No Model.)

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e' ci UNITED VSTA'rns PATENT OFFICE.

THOMAS BARROV, OF CLEVELAND, OHIO, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO CHICAGO PNEUMATIC TOOL COMPANY, A CORPORATION OF NEWF JERSEY. v

PNEUMATIC DRILL.

SPECIFICATION forming' part of Letters Patent N0. 694,714, dated. March 4, 1902.

Application filed October 29, 1900. Serial No. 34,730. (No model.)

To all whom it may concern:

Be it known that I, THOMAS BARROW, a subject of the Queen of Great Britain and Ireland, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Pneumatic Tools, of which the following is aV fullclear, and exact description, reference being had to the accompanying drawings.

The object of this inventionis to provide a very simple and efficient pneumatic tool. It is designed especially for a portable pneumatic drill.

The invention comprehends the valve employed for governing the pneumatic engines, the arrangements ofthe ports and passages for such valve, whereby the ad mission-pipe is very conveniently placed and theexhaust discharged in such direction it blows away the chips from the drill-point, the adjustment of pneumatic cylinders, and the general arrangement and construction of the parts which contribute to the efliciency of operation and economy ofconstruction. The invention may thus be convenientlysu mmarized as consisting of the combination of parts hereinafter specified, and set out in the claims.

In the drawings which clearly illustrate my invention, Figure 1 is a side elevation of the drill complete. Fig. 2 is a vertical section of the same. Fig. 3 is a top plan. Fig.` 4 is a plan with the cover-plate removed. Fig. 5 is an inner face view of the cover-plate itself. Fig. 6 is a bottom plan of the drill. Fig. 7 is a vertical section through one of the pneumatic "cylinders, being on the line '7 7 of Fig. 6. Fig. Sis a horizontal section through the ratchet feeding-lever. Fig.,9 is a perspective view of the valve-bushing, and Fig. 10 aperspective view of the valve itself.

Vithin a casing, consisting of a box A and the cover-plate A' therefor, are pneumatic driving-engines,(designated 13,) the term engine being employed as a convenient inclusive for the cylinder, piston, piston-rod, and crank 0r equiyalents therefor. These engines have individual port-openings b, which make valves with suitably-placed openings a in bosses or pads a', formed on the inner side of the cover-plate A', there being suitable passages (shown in dotted lines in Fig. 5)

within this cover-plate connecting the ports a into two groups and leading to the two admission-ports 0.2 a3, adapted to be controlled by a single valve C. Two cylinders B B are .shown,having their piston-rods b' taking onto vin the cover-plate A' and in the -base a4 of the box A. The face of the cylinders B adjacent to the port-opening b is dat, rubbing against the vbosses a' on the cover-plate, and the cylinders are nicely adj usted against this plate bythe set-,screw E2, screwing through the base to the bushing E' and bearing against an interposed plate E3 between the point of the screw and the end of the trunnion. A jamnut E4 locks the set-screw in position. As shown, the bushings E' project outside of the casing, Wherefore the pneumatic cylinders may be readjusted against their bearings to compensate for wear from the outside, as desired.

As shown, the crank-pin d, onto which the two piston rods take,v connects two diskcranks D D', from the former of which extends the main shaft d' and from the latter the bearing-shaft d2. These two shafts are journaled in bushingsvF' F2, which seat in the base a4 of the box and in the cover-plate A'.

The shaft d' is connected with the drillsocket L by suitable gearing. As shown in the drawings, this gearing isa double reduction, being by a pinion G' on the shaft d',

' meshing with a gear G2 on a lay-shaft G, and

thence via the pinion G3 in saidV lay-shaft to the gear G4 on the driven shaft G5. The layshaft is journaled in suitable bushings H' and H2, contained, respectively, in the base 0.4 of the box A and in the basejof a box J, which is secured to the platea4 for containing the gearing. Y

The driven shaft G5 is journaled likewise in a bushing K, set into the base-platej of the box J and in a bearing-block K', bolted to the lower side of that box. The driven IOO shaft G5 is [ianged over the lower edge of this bearing K', as at g', and balls I roll between them in cooperating grooves, so that the thrust on the drill-point is taken directly and without undue friction to the box J and the casing. The shaft G5 is screw-threaded on its lower end, as at g, and onto this thread screws the socket L, which receives the drill-point M, the socket being preferably locked at the thread by the pin Z, projecting through the socket and shaft G5, and the socket carrying a slot l', by which the drill-point may be keyed therein.

As stated, the engines are governed by a single valve C. This valve is placed within a bushing N, which occupies a cylindrical recess in a boss or valve-box a, formed on the upper side of the cover-plate A and preferably integral therewith. This bushing has openings n through it alining with the admission-ports t2 a3 and with the exhaust-port` a" in the cover-plate. The valve-body has a cylindrical exterior and a hollow interior and is adapted to receive compressed air in its interior and convey it to either admission-port, simultaneously connecting the other admission-port with the exhaust-port. The valve is not thus broadly claimed in thel application however, but in my application No. 34,731, filed October 29, 1900, for a valve and mechanism for operating it. The particular embodiment of that valve herein shown which I have found especially advantageous in the exacting requirements of a pneumatic drill is claimed herein and will now be described.

The valve C is rotatably mounted within the bushing N, being capable of turning substantiallyonehundred and eightydegrees therein, the movement being limited by apin c, which occupies a semicylindrical notch n2 in the end of the bushing N. Through each of diametrically opposite sides of this valve-body are formed openings and by the side thereof elongated recesses on the exterior surface, the opening and recess being reversely placed on the opposite sides of the body. Thus, referring to Figs. 2 and l0, there will be seen on oneside of the body an opening c', adapted to aline with the port-ope1iinga3,and alongside of it a recess e2, adapted to couple together the two ports a2 al, while on the opposite side of the body is the opening c3, adapted to aline with the port a2, and the recess c4, adapted to couple together the ports a3 a7. Thus if air under pressure is admitted to the interior of the valve it may pass to either admission-port of or a3 and the other admission-port be coupled with the exhaust-port a7, according to the positionof the valve, the simple turning 0f the valve through one hundred and eighty degrees accomplishing this change, and a position of it intermediate thereof-that is, ninety degrees from either extreme-closing all ports.

Air under pressure comes to the interior of the valve as follows: Around the exterior of this valve beyond the ports is an ann ular rccess c5, which is connected with the interiorof the valve by a pair of openings c6. This annular recess is in constant communication through an opening n in the bushing N with a passage a8 through the cover-plate, which alines with a bent opening a9, formed through suitable bosses in the vertical wall ai of the box A and extending laterally to the outside of the box, into which is adapted to be screwed the flexible admission-pipe Q. This provides for a very convenient location of the admission-pipe. It is neither in the way of the object being drilled nor of the upper support against which the drill bears. It is not likely to be bent abruptly, and it may conveniently serve as a handle for carrying the drill and holding it in place. The valve becomes perfectly balanced, since the same surface is presented to the air at all points, the compressed air entirely surrounding the Valve in the re-e cess ci and the area of the two openings c' c3 being on diametrically opposite sides of the valve, counterbalancing each other.

The valve is held in place within the bushing by the pin c, abutting against the periphery of the notch c2, and the shank c7, taking through a plug n3 in the end of the bushing and having the operating-lever C' secured to this shank against the outer side of the bushing. The simple turning of this lever C' in one direction or the other thus controls the pneumatic engines.

The exhaust-port a7 with which the exhaust ends of the two cylinders are in connection through the valve C leads from just below the valve-box through a pair of branch pipes a", preferably made integral with the coverplate A on its outer side, to the edge of that plate. At the end these pipes a turn downward, terminating at the lower face of the cover-plate A. They thus leave the openings ct2 for the discharge of the exhaust-air in the direction toward the point of the drill M, with the result that the stream of air strikes the work being drilled substantially at the drill-point and blows away the chips. This is an important feature, as it obviates the necessity of any extraneous means for disposing of the chips and at the same time does not require any external piping to convey away the exhaust-air, nor is that air discharged in such a direction as to be any inconvenience to the operator.

A convenient handle for the drill is provided on the opposite side from the pipe Q by the tubular bar R, which screws into the threaded bushing R', set into a boss formed 0n that side of the wall d5 of the box A.

By journaling the various parts in bushings, as shown, not only is a very satisfactory bearing for the rotating parts obtained, but the box A, its cover-plate, andthe box J may be constructed of aluminium, thereby lightening the drill and making it more easily portable.

The drill complete is fed to its work by the following mechanism: @n thc upper side of IIC theV plate A', axially ofv the driven shaft G5,

isthe screw-threaded stud P, supported by the plate p, bolted to the cover-plate. Engaging with this stud by internal vthreads is the barrel S, having its upper end coming to a conical point. On the outer side of this barrel is formed an annular collar s', and above thisfcollar. is the notched or toothed sleeve s2, rigid withthe barrel S, the notches being radial and leaving square teeth between them. Loosely surrounding the toothed sleeve is the strap t, which is the integral end ofthe feeding-lever T. Thisstrap is held in place bythe nut s3, screwing onto the barrel S. Axially within thelever Tis the pawl-bar U, which has at its inner end a tooth u, adapted to take between the teeth s2, the bar being spring-pressed toward the same. This tooth u is formed by cutting a notch through half of the rod U at its end and beveling the remaining half to a diametric edge, wherefore one face of the tooth lies in the radial plane of the sleeve s2 and the other face is at an angle thereto. It thus results that when the lever T is moved in the direction to cause the radial face of the toothu to engage a tooth's2 the latter tooth, and hence the barrel S, is rotated; but when the lever T is moved in the opposite direction the inclined face of the tooth u, engaging the edge of a tooth 82, may be forced backward thereby without vrotating the sleeve s2 or the barrel S. The spring which forces the rod u toward the sleeve s2 is preferablya helical spring V, surrounding arreduced shank u on the rod U and compressed between the shoulder thus formed on the rod, and a head or nut t', secured to the end of thelever T. The shank u projects through the nut and has on its outer end ahead u2, which carries on its inner face a pin n3, adapted to occupy either of two diametrically opposite recesses t2 in the head on nut t. The engagement of this pin in the recess prevents the turning of the rod U, and the spring V holds the latter in engagement with the toothed sleeve s2. When it is de-- sired to have the leverTturn the barrel S in the opposite direction, the'head u2 is pulled outward, releasing the pin us from the recess i2, which it occupied, whereafter a turn of the head through one hundred and, eighty degrees bringsthe pin u2 into alinement with the other recess t2 and reverses the position of the tooth u. The radial face of this tooth u, being on a diametric plane through the rod U, occupies the same position in each of the positions of this rod, the body of the tooth back of that face being in one direction or the other therefrom, according to the direction in which it is desired to rotate the barrel S.

Having described my invention, I claiml. In a pneumatic tool, the combination of a casing, an engine within the casing adapted to drive the tool, a cover-.plate for the casing having valve-passages leading to the engine,

a valve-box formed on the outer side of said `substantially, as described.

cover-plate, a hollow valve within said box having an' opening from its interior for the admission, and a recess in its exterior, a passage through said cover-plate to said valvebox adapted'to be in openr communication with the operating fluid, an opening into the interior of the valve in communication with said entrance-opening in both of the operating positions of the valve, substantially as described. l

2. In a pneumatic tool, the combination with a casing, an engine within the casing adapted to drive the tool, passages leading to said engine, a rotary valve forcontrolling said passages, said valve consisting of a hollow barrel having a pair of admission-openings from its interior to its exterior on opposite sides of it and havinga pair of recesses also on opposite sides for connecting the other passage with the exhaust, the position of the admission-opening and the exhaust-recess on the opposite sides of the valve-barrel being reversed, and an opening fort-he admission of operating iiuid to the interior of said valve, substantially as described.

3. In a pneumatic tool, the combination of a driving-engine, an oscillating valve for con` trolling the direction of operation of said engine, which valve consists of a hollow barrel having a pair of admission-openings through it and exhaust-recesses on its outersurfaco, one opening and the corresponding exhaustrecess being placed in the barrel in the reversed position from the other opening of its corresponding recess, a circumferential re'- cess in said` barrel, an opening from said recess into the interior of the barrel, and a passage-way for operating fluid alining with said last-mentioned recess, substantially as specified.

4. In a pneumatic tool, a casing, van engine within the casing adapted to drive the tool, a valve-seat circular in cross-section, passages leading from said seat to the engine, an exhaust-passage leading from said'seat, the ports to said passages in the seat being in the same side of the seat, combined with an oscillating valve occupying said seat and consisting of a hollow barrel having a pair of IOO IIC

admissionLopenings from its interior to its exterior and on its exterior' surface exhaust'- recesses, each admission-opening and its cor'- responding exhaust-recess being oppositely arranged longitudinally of the valve from the other admission-opening and its recess, and thereY being an opening for the admission of operating fluidv to the interior. of said valve,

5.In apneumatic tool, a casing, an engine within the casing, passagesv leading to the engine, a valve-seat with which said passages communicate by port-openings, an exhaustpassage commonto both ad mission-'ports and having a port in said seat between the admission-ports,said seat bein g circularin crosssection, combined with a hollow rotatable plug occupying such seat and having a pair ISO of admission-openings through its wall, one adapted to cooperate with one admission-port in the seat in one position of the valve and the other adapted to cooperate with the other admission-port in the other position of the valve, said plug having exhaust recesses adapted to overlap the two remaining ports of the seat when either admission-port and the corresponding valve-opening are coupled, said two admission-openings and the corresponding recesses for the two operations being relatively reversed in their longitudinal positions on the valve-body, substantially as described.

6. In a pneumatic tool, the combination of a casinghavinga cover-plate,an engine within the casing,passages leading through the coverplate to the engine, a valve-seat on the outer side of the cover-plate with which said passages communicate by port-openings in alinexnent, an exhaust-passage having a port in said alinement, said seat being circular in cross-section, and a hollow rotatable plug occupying such seat and having a pair of admission openings through its wall out of alinement both longitudinally and circumferentially, and one adapted to cooperate with one admission-port in the seat in one position ot' the valve and the other adapted to coperate with the other admission-port in the other position of the valve, said plug having exhaust-recesses longitudinally alined with its admission-openings and adapted to overlap the two remaining ports when either admission-port and the corresponding valve-v opening are coupled, said two admissionopenings and the corresponding exhaust-recesses being in reversed alinement, substantially as described.

7. In a pneumatic tool, the combination ot' acasinghavingacover-plate,an engine within the casing, passages leading through said cover-plate to the engine, a valve-box on the outer side of the cover-plate with which said passages communicate, said passages terminating in a row with an exhaust-passage in the side of the box adjacent to the cover, said box havingits interior circular in cross-section, a hollow rotatable plug occupying such interior and having a pair of admission-openings from its interior to its exterior on opposite sides of it and having a pair of recesses also on opposite sides for connecting the other passage with the exhaust, said admissionopening and exhaust-recess being alined on each side of the valve but said parts being in reversed relative position 011 opposite sides, there being an opening for the admission of operating liuid to the interior ot the valve, substantially as described.

S. In a pneumatic tool, in combination, an engine, a casing inclosing said engine, said casing consisting of a box with a cover-plate therefor, valve-passages through the coverplate leading to the engine-ports, a valve-box on the outer side of the cover-plate for controlling said passages, a valve in said box, a main admission-passage through the coverplate from the valve-box to the inner face of the cover-plate, and an admission-passage in the casing-box itself alining with such passage in the cover-plate and opening outward, and means for securing an ad mission-pipe at the said outward opening, substantially as described.

9. A pneumatic tool including an engine and a spindle adapted to be rotated thereby and having a discharge-passage from the engine adapted to direct the discharged air toward the free end ot the spindle, substantially as described.

10. In a pneumatic tool, a casing consisting of a box and a cover-plate therefor, an engine within the box adapted to drive the tool, a valve on the outer side of the coverplate, ad mission and exhaust passages leading from said valve through the cover-plate to the engine, a main admission-passage leading to said valve, and a pair of exhaust-passages branching from the valve and leading to the edges of the cover-plate on opposite sides of the tool and turning across such edges in the direction pointing toward the tool-point, substantially as described.

1 l. In a pneumatic tool, the combination of a casing consisting of a box and a cover-plate, oscillating engines within such casing pivoted on trunnions taking into the box and coverplate, a driven shaft and connecting mechanism between it and said engines, the trunnions of the engines occupying bushings carried by the casing, a set-screw passing axially through one of these bushings, and an interposed plate between the set-screw and the end of the trunnion, substantially as described.

12. In a pneumatic tool, the combination of a casing, oscillating engines within the casing pivoted on trunnions and having their pistons operating on the same crank-shaft, said crankshaft extending outside the casing, a box secured tothe casing and containing reducinggearing, a driven shaft extending outside of the box and connected by such gearing within the box with the main shaft, bushings in which the trunnions of the oscillating engines seat, which bushings extend through the base of the casing outside of the box containing the reduced gearing, and means carried by said bushings for adjusting the engines toward the opposite side of the casing, whereby such adjustment may be made from the outside with the parts in place, substantially as described.

In testimony whereof I hereunto ax my signature in the presence of two witnesses.

THOMAS BARROVV.

Vitnesses:

ALBERT II. BATES, Il. M. WISE.

IIO 

